SWMM Time Patterns

SWMM Time Patterns are database items which are used in SWMM networks to allow external Dry Weather Flow (DWF) to vary in a periodic fashion. They consist of a set of adjustment factors applied as multipliers to a node's baseline inflow rate or pollutant concentration. There are 4 types of time patterns that can be specified:

• Monthly - one multiplier for each month of the year
• Daily - one multiplier for each day of the week
• Hourly - one multiplier for each hour of the day from 00:00 to 23:00
• Weekend - hourly multipliers for Saturdays and Sundays

Each dry weather inflow (either flow or pollutant) can have up to four patterns associated with it, one for each type listed above.

Time patterns are viewed and edited using the SWMM Time Patterns Editor.